I am trying to access a CalDAV account in iCal and everything works fine except for the Delegation tab. I can see the account(s) I have access to (including the correct read/write properties), but the checkboxes are disabled and the calendars cannot be selected. Has anyone seen this before & know what the cause is?
This is a custom CalDAV implementation, so it is likely due to a disconnect between what iCal expects and what our server is sending -- but there are no error/warning messages in the console to indicate what the problem might be.
Any advice would be appreciated.
iCal queries the permissions and methods available on the server. To query the permissions on a collection resource you will need to have the DAV::read-current-user-privilege-set permission. Assuming iCal can read the permissions it will be looking for the DAV::read permission for reading and the DAV::bind, DAV::unbind and DAV::write permissions to indicate the ability to write.
The best way to debug this is probably to read RFC3744 about half a dozen times, interspersed with using iCal against a working server and sniffing the TCP communication as it does it. A good way is to use some kind of man-in-the-middle proxy so you can sniff the communication with (e.g.) Mobile Me or iCloud.